1. Field of Invention
The invention relates to a common two-prong and three-prong socket AC power receptacle. More particularly, it relates to a multi-socket receptacle that has three-prong sockets on the top surface and two-prong socket on one side surface of the receptacle casing. Through appropriate arrangement of the sockets, space can be utilized in a better way.
2. Related Art
In modern society, people have a larger demand for electronics for a more convenient lifestyle. Since each electronic device needs at least one socket for electricity, more sockets are needed on a receptacle.
The traditional multi-socket receptacle has a casing composed of an upper lid and a bottom casing. A series of sockets are provided on the upper lid. A power cord with a plug on a distal end extends out of one end of the casing. This kind of multi-socket receptacle design and configuration has been used for a long time. The available sockets on a single receptacle are often insufficient for practical application. A typical computer system may require a lot of sockets. Furthermore, peripheral devices such as modems, speakers and scanners often use adapters with a larger volume than ordinary plugs. When one of such adapters is plugged into one socket of the multi-socket receptacle socket, adjacent sockets are often blocked. Therefore, the conventional multi-socket receptacle is very inconvenient for such applications.
For an ordinary computer user, an extension cord with multiple sockets is definitely required when even basic peripheral devices are included. However, such devices usually have different types of plugs. Basically, computers and printers use three-prong plugs, and other peripheral devices use two-prong plugs. If the user gets an extension cord with two-prong sockets, three-prong plugs cannot be plugged into the receptacle. At this point, most users obtain three-prong-to-two-prong converters, while others just ignore the ground pole and cut it off the plug. The later method totally negates the protection provided by the ground prong on the plug. Also, some merchants simply take off the ground prong from the plug. Although this method solves the problem of plugging three-prong plugs into two-prong sockets, the ground protection is lost. Furthermore, even if the user purchases a new three-prong socket, the grounding protection cannot be restored to the broken plug.
As a practical matter, some peripheral devices are turned on only when necessary. That is, they are often turned on and off at the same time. However, some other devices have to be turned on all the time (e.g., modems, UPS, etc). If a receptacle without a switch or switches is selected for use, then the plugs or adapters for the devices not in use have to be unplugged. The plugs have to be stored at some corner of the computer desk before being plugged back in for the next use, or the user has to find the switches at various places on those devices and turn them off individually. This is indeed very inconvenient in operations. If the user selects a receptacle with multiple switches, then he or she has to turn them off one by one. Despite the fact that it is more convenient than the receptacle without any switches, there is still some risk of turning on or off the wrong device.
Accordingly, an objective of the invention is to provide a common two-prong and three-prong AC power receptacle. Several pairs of sockets are provided on the top and one side surface of the casing. A switch is mounted on one end of the casing. The sockets on the top surface are three-prong and the ones on the side surface are two-prong. Some of the sockets are directly connected in series to the power cord and are electrically xe2x80x9chotxe2x80x9d all the time. A switch is connected in series between the power cord and the other sockets. The switch controls whether they are conducting. This design can provide users more sockets to use and better controls.